An optical pickup device is a device for recording (writing) and erasing information in the way that laser light emitted from a semiconductor laser element as a light source is converged with an objective lens onto a signal recording surface of an optical disc, and for reproducing information in the way that reflection light (returning light) coming from the signal recording surface is detected with a photodetector.
Corresponding to the trend of downsizing an optical disc apparatus, there have been proposed techniques of downsizing optical pickup devices from various view points, too. As one of them, Patent Literature 1 discloses a technique that a layered member for controlling a phase difference is arranged on a beam splitter or a raising mirror to eliminate a wavelength plate.